1. Field of Use
This invention relates to the data processing field and more particularly to data communications software which connects the data processing system to a variety of terminals requiring different communication technologies.
2. Description of the Prior Art
Over the years the data processing systems have changed from batch processing applications to interactive system applications. In a batch processing application, all of the processing is done at the computer site including all input into the data processing system.
As the technology improved, particularly in the terminal area, operators at remote terminals would key into their terminal and the information would be transferred to the central computer over communication lines. This required communication controllers at the computer site and software to drive these communication controllers. The software developed at that time was written in a low level assembly language, was designed for use with a specific communications technology and further designed to provide specific modes of application support. The terminals were also limited by having fixed data code characteristics.
This type of communication's controller hardware and software design presented a number of problems. The software was very difficult to maintain and modify. This is particularly true if the software had to be extended to support a new terminal which was added to the system.
Today terminals are being built with new and evolving technology in the communications area. However, the software in the central system is too rigid to adapt to these new technologies. If these terminals require extended modes of application support, it is difficult to adapt the software.